iSQI CTFL_Syll_4.0 Exam With Confidence Using Practice Dumps

The question is about marking the correct sentences among the given statements related to defects, failures, and mistakes. According to the ISTQB glossary, the definitions of these terms are1:

Defect: A flaw in a component or system that can cause the component or system to fail to perform its required function, e.g. an incorrect statement or data definition. A defect, if encountered during execution, may cause a failure of the component or system.

Failure: An event in which a component or system does not perform a required function within specified limits.

Mistake: A human action that produces an incorrect result.

Therefore, out of the five given statements, only two are correct, namely:

A human mistake may produce a defect: This is true, as a mistake is a source or cause of a defect, e.g. a programmer may make a mistake in writing a code statement, which results in a defect in the software component.

When a defect exists in a system it may result in a failure: This is true, as a defect is a potential or actual cause of a failure, e.g. a defect in the software component may cause the system to fail to perform a required function when the defect is encountered during execution.

The other three statements are incorrect, namely:

Defects are a result of environmental conditions and are also referred to as “Failures”: This is false, as defects are not a result of environmental conditions, but of mistakes or other factors, and defects are not the same as failures, but rather the causes of failures.

A system will totally fail to operate correctly when a failure exists in it: This is false, as a system may not necessarily fail completely or stop operating when a failure occurs, but may continue to operate with reduced functionality or performance, or with incorrect results.

Defects occur only as a result of technology changes: This is false, as defects can occur due to various reasons, not only technology changes, such as human mistakes, design flaws, requirement changes, hardware failures, etc.

Comprehensive and Detailed Explanation From Exact Extract:

This question applies theState Transition Testingtechnique.

Let’s evaluateOption Dstep-by-step:

NORMAL MODE → DEGRADED MODE:✅Valid on“FAILURE DETECTED”

DEGRADED MODE → NORMAL MODE:✅Valid on“ALL FAILURES CLEARED”

NORMAL MODE → DIAGNOSTIC MODE:✅Valid on“SELF DIAGNOSTIC INITIATED”

DIAGNOSTIC MODE → DEGRADED MODE:❌Invalid– there isno defined transitionfrom DIAGNOSTIC MODE directly to DEGRADED MODE.

According to the state diagram, DEGRADED MODE can only be entered:

From NORMAL MODE (on FAILURE DETECTED), or

Not from DIAGNOSTIC MODE at all.

This violates the rule:

“State transition testing uses a model where test cases are designed to execute valid and invalid transitions.”

(ISTQB CTFL Syllabus v4.0, Section 4.2.4 – State Transition Testing, Page 40)

Thus, OptionDcontains aninvalid transition, making it the correct answer.

Comprehensive and Detailed Explanation From Exact Extract:

From the user story analysis and final achievements:

It was confirmed that dues were paid monthly for over a year, whichcovers criteria 1, 2, 3, 5, 6, 7, and 8.

However, there isno mention of testing for “annual payment”, soacceptance criteria 4, which involveschoosing between monthly or annualpayment, wasnot fully tested.

This reflects the requirement stated in:

“Acceptance criteria are used to: Define the scope… Describe both positive and negative scenarios… Serve as a basis for the user story acceptance testing.”

(ISTQB CTFL Syllabus v4.0, Section 4.5.2, Page 45)